A more practical approach is to consider that the interaction with the layered geometry is mediated by the average scattered field from the particle monolayer in the uniform background [1]}. In other words, the particle monolayer is treated as planar interface with reflection and transmission coefficients given by \(r_\text{coh}\)  and \(t_\text{coh}\) , and the reflection and transmission coefficients of the entire structure are determined by classical formulas of electromagnetic waves in layered media [2]}. In addition to the approximations made at the level of the particle monolayer only, the mutual interaction between particles via the interfaces of the environment is therefore discarded in this approach, which may be problematic in certain situations, for instance, when incident planewaves couple efficiently to guided (photonic or plasmonic) modes in the layered medium.
